GROWTH AND PHOTOSYNTHETIC RESPONSE OF FOUR MALAYSIAN INDIGENOUS TREE SPECIES UNDER DIFFERENT LIGHT CONDITIONS

Abstract

Kenzo T, Yoneda R, Matsumoto Y, Mohamad Azani A & Nik Majid M. 2011. Growth and
photosynthetic response of four Malaysian indigenous tree species under different light conditions. Growth
and photosynthetic response of four indigenous tree seedlings, i.e. Dyera costulata, Dipterocarpus baudii,
Neobalanocarpus heimii and Gonystylus affinis were studied under different light conditions in a degraded
secondary forest. Maximum photosynthesis (A_max) was measured at 2 and 12 months after planting. The
ratio of variable to maximum fluorescence (F_v/F_m) was determined. Leaves measured at 2 and 12 months
after planting were old leaves present on the seedlings and new leaves that had expanded after planting
respectively. Seedling growth was measured over four years. Changes in the growth rate and A_max with canopy
openness were categorised into two groups. The growth and A_max of the first group (D. costulata and D. baudii)
were maximum at 30–40% canopy openness. This group may be suitable for planting under large canopy
gaps. The second group (G. affinis and N. heimii) showed maximum growth and A_max at relatively low canopy
openness (less than 20%). Leaves in the second group suffered chronic photoinhibition under large gap.
These species were suitable to be planted under low light conditions.